SPY vs. IVV vs. VOO: S&P 500 Holdings and Basket Analysis

This guide answers a practical question: if SPY, IVV, and VOO all follow the S&P 500, what actually differs? It does not rank returns or recommend a ticker. We compare the equity positions disclosed for the same reporting date, the largest stock weights, and how holding more than one of these funds changes an investor’s exposure. Current fund details come from the sponsors and can change after this snapshot.

We keep security counts separate from portfolio dollars. Two funds can hold the same security while owning different share quantities and assigning it slightly different net-asset weights. Similar company names are not enough to merge positions: Alphabet Class A and Class C have separate ISINs and remain separate securities in this comparison.

SPY is the State Street SPDR S&P 500 ETF Trust, IVV is the iShares Core S&P 500 ETF, and VOO is the Vanguard S&P 500 ETF. They have different sponsors and fund structures, but each seeks to track the S&P 500. The comparison therefore starts with a shared benchmark, not merely the fact that each name contains “500.” See the sponsor pages for VOO, IVV, and SPY.

The S&P 500 covers large U.S. companies, with constituent weights based on float-adjusted market capitalization. A larger company can therefore affect the index and these funds more than a smaller constituent. “500 companies” does not mean 500 equal positions. The index is also a calculation, not a fund that owns every share: index rules maintain a continuous measure through additions and removals, while an ETF is a separate portfolio designed to track it. See the S&P U.S. index methodology and the S&P 500 overview.

All three SEC Form N-PORT files report positions as of June 30, 2026. We kept equity-category positions, grouped duplicate lines, and matched securities by ISIN first. Different share classes, such as Alphabet A and C, kept separate identifiers. When ISIN was unavailable, CUSIP or LEI fields were checked so a blank or generic value would not merge unrelated holdings. The source files are the Vanguard 500 Index Fund filing that includes VOO, the IVV filing, and the SPY filing.

VOO’s filing is reported at the Vanguard 500 Index Fund series level. VOO is an ETF share class of that fund, so the series’ entire net asset figure should not be described as VOO-only assets. We use the disclosed position weights and identifiers, not that series total as a ticker-specific asset figure. IVV and SPY filings identify their respective ETF products. Even with a common reporting date, we do not assume that the three funds calculate position percentages, rounding, or net-asset denominators identically.

The top positions appear in nearly the same order. On June 30, 2026, the ten largest equity positions totaled 36.40% of VOO net assets, 36.36% of IVV, and 36.42% of SPY. Rows below round the filed weights to two decimal places; each total uses unrounded figures, so adding the displayed rows may differ slightly.

The close weights show that these funds share much of the same large-company exposure. The table does not predict one fund’s next return from another’s recent result. It is a one-date holdings comparison, not an investor-return calculation that includes later price changes, distribution reinvestment, fund expenses, and execution prices.

Using ISIN to match equity positions, IVV and SPY each had 503 security identifiers; VOO had those same 503 plus three additional position identifiers. One was Conagra Brands, at 0.00865% of VOO net assets. The other two were contingent value rights (CVRs) left in the filing, together below 0.000004%. The filings alone do not explain why the Conagra residual remained or establish that it represents an intentional portfolio tilt. It would be misleading to treat these small rows as a distinct strategy.

The reported weights for the 503 securities shared by all three funds sum to 99.74% of VOO net assets, 99.83% of IVV, and 99.98% of SPY. Total disclosed equity weights were 99.75%, 99.83%, and 99.98%, respectively. The small remainder can include cash or other non-equity items. VOO’s common-weight total is below 100% in part because of the residual positions and non-equity assets.

This comparison uses ISINs and checks CUSIP and LEI fields when necessary; it does not infer matches from company names alone. A non-U.S.-incorporated share can have a different CUSIP representation across filings yet share the same ISIN. Treating N/A as a valid identifier could incorrectly combine unrelated securities, while matching only by name could miss different share classes.

For equal-dollar positions, a security’s blended weight is the average of its weights in the funds. Suppose an investor puts $10,000 into each ETF, for $30,000 total. NVIDIA was 7.5142% of VOO, 7.5059% of IVV, and 7.5170% of SPY. The combined NVIDIA exposure is about $2,253.72, or 7.5124% of the ETF total. Rounded for display, that is about $2,254 and 7.51%.

There are three tickers in the account, but the 503 shared stocks are not three separate markets. Position weights may vary slightly; most of the underlying company exposure is repeated. Moving from one ticker to another can change the fund wrapper, expense ratio, or trading conditions without adding a new country, bond, commodity, or small-company asset class.

More generally, if amounts a, b, and c are invested in funds A, B, and C, and a security has weights wA, wB, and wC, its blended weight is (a×wA + b×wB + c×wC) ÷ (a+b+c). An exact current exposure also changes with holdings and prices after purchase. This example freezes June weights; it is not a forecast of returns or whole-account risk.

Sponsor materials list different expense ratios: Vanguard showed 0.03% for VOO as of April 28, 2026; iShares lists 0.03% for IVV; State Street lists a 0.0945% gross expense ratio for SPY. These figures can change, so check the latest fund documents before trading.

If a $10,000 balance stayed unchanged for a full year, 0.03% would be about $3 and 0.0945% about $9.45. The difference between SPY and VOO or IVV would be about $6.45 per year at that balance. Expenses are reflected in fund assets rather than billed as a fixed invoice, and dollar cost changes as the balance changes. This illustration excludes bid-ask spreads, broker charges, taxes, currency conversion, and tracking difference.

The lowest stated expense ratio is not automatically the best choice for every investor. Trade timing, available quotes, account features, options use, dividend-reinvestment settings, taxes, and holding period can affect total cost. Continue with ETF expense ratio versus total cost and ETF trading volume versus liquidity for those separate mechanics.

VOO is an ETF share class of Vanguard 500 Index Fund. Its SEC filing is therefore at the fund-series level, which is why we did not label the entire series’ net assets as VOO-only assets. IVV is the iShares Core S&P 500 ETF. SPY is a Unit Investment Trust (UIT) registered under the Investment Company Act. Its UIT form and unit structure appear in the January 2026 prospectus.

Most individual investors buy or sell ETF shares on an exchange. Fund creation and redemption is a separate process that authorized participants handle in creation-unit sizes. An ETF’s market price can differ slightly from NAV during the day, and an investor’s execution depends on quotes, order size, and market conditions. A fund name or average volume does not guarantee the execution cost at a particular moment. Different legal structures also do not turn the same underlying companies into three independent markets.

VTI seeks broad U.S. market exposure, while VOO tracks the S&P 500’s large-company index. VTI reaches smaller companies as well, though market-cap weighting still gives large companies substantial weight. In the June 2026 filings, 503 stock CUSIPs appeared in both VTI and VOO; those shared positions represented 99.61% of VOO net assets and 88.09% of VTI. Read the related VTI and VOO basket analysis to distinguish overlap among S&P 500 funds from the overlap involved in adding a total-market fund.

Adding SPY, IVV, or VOO beside an existing VTI holding can intentionally raise large-company exposure. Adding multiple S&P 500 tickers mostly repeats the same index constituents, so counting each fund as a separate diversification source can understate company-level weights. Decide whether the goal is more U.S. large-cap exposure or a different asset group, such as smaller companies, international stocks, or bonds, and total each company’s exposure across the actual account.

The June 30, 2026 filings show 503 equity securities in common and top-ten weights near 36% for all three funds. The expense ratios and legal structures differ, but holding these tickers together mostly repeats the same large-company exposure.

The 503-security match is not a correlation coefficient, a return forecast, volatility, maximum drawdown, or a measure of an investor’s full account risk. Those require separate calculations with a defined period, currency, return frequency, and treatment of distributions. Holdings change with index membership, corporate actions, trades, and cash. Do not treat this dated snapshot as a permanent composition or evidence of future returns. For later checks, use the linked issuer pages and ETF tracking difference versus tracking error.